Rotary regenerator matrix with stiffeners of low temperature gradient



May W, W67

LULTEJILTMANN 3,51%,Wa ROTARY REGENERATOR MATRIX WITH STIFFENERS OE LOW TEMPERATURE GRADIENT Filed Aug. 11, 1966 v-/@ INVENTOR.

United States Patent ROTARY REGENERATUR MATRIX WiTH STIFF- ENERS 0F LDW TEMPERATURE GRADIENT Clarence F. Luedemann, Indianapolis, Ind, assignor to General Motors (Iorporation, Detroit, Mich, a corporation of Delaware Filed Aug. 11, 1966, Ser. No. 571,856 4 (Ilaims. ('Cl. 165--8) This application is a continuation-in-part of my application Ser. No. 391,426 for Cooled Seal, filed Aug. 24-, 1964, now abandoned.

My invention relates to heat exchange apparatus and particularly to an improved rotary regenerator matrix structure.

In a preferred type of rotary regenerator, a cylindrical matrix has compartments formed by the rims of the matrix and radial partitions or stitfeners which extend between the rims. The compartments contain heat transfer material which, as the rotor turns, is first exposed to hot gases to absorb heat therefrom and then exposed to air to impart heat thereto.

In operation, the usual temperature differential across the matrix causes thermal distortion in the matrix, hereby diminishing the effectiveness of the seals associated therewith. The use of relatively thick steel plates for the matrix stiifeners in these regenerators has been common practice, but this does not prevent a high temperature gradient across each stiffener and a tendency for such stiffeners to distort in operation.

To overcome this undesirable distortion, the present invention contemplates the use of means designed to reduce the temperature gradient within the stiifeners. In general, the subject invention contemplates a stiifener for a rotary regenerator which comprises several cooperating elements rather than the conventional one-piece construction. The present invention provides a multi-piece stiffener which includes its own internal retroverse flow path to reduce thermal distortion. The stiffener includes two bars having relieved areas therein which cooperate to form a flow path between the bars. A sheet metal bafiie arrangement is placed in the space between the bars to form a multi-pass flow path through the resulting stiffener structure.

Thus, it is an object of my invention to provide a rotary regenerator matrix structure which reduces the thermal distortion due to temperature gradients within the structure.

It is another object of my invention to provide a matrix stiffener which is constructed of a plurality of cooperating parts which define a flow path through the stiffener.

It is a further object of my invention to provide a stiffener for a rotary regenerator which is comprised of a plurality of parts cooperating to form a stiffener with a multipass flow path therethr-ough which reduces the temperature differences in the stiffener and thereby reduces distortion.

Other objects, features, and advantages of my invention will become obvious upon reference to the following detailed description and the drawings illustrating the preferred embodiment thereof.

FIGURE 1 is a perspective view of a radial-flow rotary regenerator matrix incorporating the invention.

FIGURE 2 is a sectional view taken in the direction of arrows 2-2 in FIGURE 1 showing the stiffener in section.

FIGURE 3 is a sectional view of the component parts of the matrix taken in the direction of the arrows 33 in FIGURE 2.

FIGURE 4 is an end perspective exploded view of the subject stiffener.

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FIGURE 5 is a schematic representation of a radialfiow rotary regenerator.

Referring first to FIGURE 5, a conventional rotary regenerator of the sort to which my invention may be applied may include a case or housing -1 having an inlet 2 and an outlet 3 for air to be heated and having an inlet 4 and an outlet 5 for hot gas such, for example, as an exhaust from a turbine. The interior of the housing is divided into an air section and a gas section by a fixed diaphragm 6. An annular regenerator matrix 10 is mounted and rotated by means not illustrated so that any given portion of the matrix moves successfully through the exhaust gas and the incoming air. Seals 7 are provided where the matrix passes through the diaphragm to minimize leakage of the air to exhaust. The air flows from the outer face 8 of the matrix to the inner face 9 and the gas flows from the inner face to the outer face.

Referring now to FIGURE 1, the matrix 10 has end rims 12 defining the margins of the matrix between which are mounted the various units 14 of the matrix structure. As seen in FIGURE 1, the matrix structure 14 comprises a plurality of heat exchange units 16 permeable to gas flow radially of the matrix separated by stitfeners 18. This invention is primarily concerned with the structure of the stiffener 18 as shown in detail in FIGURES 2 through 4.

As seen in FIGURE 4, the stiffener structure 18 includes two bars 20 and 22. These bars are constructed such that their parts cooperate to form a flow passage between the two bars. A pair of sheet metal baffles 24 and 26 are inserted between the bars 20 and 22 in the flow passage. The bar 20 has a plurality of holes 28 in its upper flange portion 30' which align with openings 32 and 34 in the upper portions of the baffles 24 and 26, respectively. Similarly, the bar 22 has a plurality of holes 36 in its lower flange portion 38 which align with openings 40 and 42 in the bafiies 24 and 26. Hence, "when the two bars 20 and 122 and the bafiies 24 and 26 are put together, the aforementioned openings aling to form a radial flow path through the stiffener 18. One such flow path shown in FIGURE 3 begins at 44 in holes 28. The upper and lower margins of the baffies 24 and 26 are formed so that they cooperate to form flow paths 46, 48, and 50 in the space between the bars 20 and 22. As seen in FIGURE 4, a plurality of holes 52 extend through the baffle 24 near its upper edge and a plurality of holes 54 extend through the baffie 26 near its lower edge. These holes 52 and 54 cooperate with holes 28 and 36 to form the entrance and exit paths for the gas flowing through the stiffener 18.

As further seen in FIGURE 4, bar 20 has a boss 56 with a bore 58 through it and bar 22 has a boss 60 with a bore 62 through it. Bosses 56 and 60 form the means by which the two bars are secured together and to the rim 12 by a pin 64 shown in FIGURE 2. The pin 64 is lodged at its upper and lower ends in the end rim 12 and passes through the bosses 56 and 60. The opposite margin of the matrix has the same structure.

The function of my stiffener structure can best be understood by examination of FIGURE 3. The inner diameter or face 9 of the matrix is at the bottom of the figure, while the outer diameter or face 8 is at the top. As shown by the arrows in FIGURE 3, air can enter at the outer face 8 and pass through the openings 28 in the bar 20 and then flow into the channel 46 through the openings 32 in the upper portions of the bafiles 24 and 26. The air moves down the channel 46 between the bafile 26 and the bar 22 and then flows through the openings 54 near the lower edge of the baffle 26 into the channel 48. The air then flows upward through the channel 48 between the two baffles 24 and 26 and then through the openings 52 in the upper edge of bafiie 24 into the channel 50. The air then flows down through the channel 50 between the baflle 24 and the bar 20 and passes through the openings 40 and 42 in the lower portions of the bafiles 24 and 26 and through the openings 36 in the lower flange 38 of the bar 22 to reach the inner face 9. Hence, it can be seen that a three-pass flow path indicated generally at 44 is formed within the stiffener bar construction 18 so as to allow the gas which is flowing through the adjacent matrix structures to also flow through the stiffener bar in a retroverted path, thereby reducing the temperature gradient across the stiffener bar and the thermal distortion resulting therefrom. The gas flows through the stiffener in the same path as the air, but in the opposite direction, radially outwardly in the illustrated embodiment.

It might be mentioned further that a seal 68 may be installed adjacent to the stiffener 'bar 18 so as to provide the required sealing effect between the matrix and the adjacent seals 7. The use of the seal is purely a matter of design and is dependent upon the specific application.

Summarizing, the subject invention provides a stiffener structure which contains its own gas flow path for stabilizing the temperatures within the stiffener bar and reduces the thermal distortion therein so that the subject stiffener bar can be combined with well-known heat exchanger matrices to form an effective rotary regenerator for a turbine.

Although but one specific embodiment of the subject invention has been described and shown in detail, it should be clear to those skilled in the art to which the invention pertains that many changes and modifications may be made thereto without departing from the scope of the invention.

I claim:

1. An annular matrix for a rotary regenerator comprisflow path starting at one edge of the stiffener and terminating at the other edge of the stiffener, for circulating fluid through the stiffeners from edge to edge in response to the pressure gradient operative to cause fluid flow through the heat exchange material from face to face of the matrix, said stiffener structure including 7 two bars disposed face to face, at least one bar being recessed to define a passage within the stiffener extending in the edge-to-edge direction of the stiffener means defining holes in both edges of the stiffener communicating with the said passage and baffie means within the passage defining a retroverse path with an odd number of mutually overlapping passes for the fluid in the direction from edge to edge of the stiffener within the passage.

2. A matrix as defined in claim 1 in which the baffle means includes an even number of sheets extending generally in the directions from rim to rim and from edge to edge of the stiffener, the sheets being spaced from each other and from the beams to define the said overlapping passes.

3. A matrix as defined in claim 2 in which the sheets include bent-over marginal portions abutting the beams to locate the sheets and partially spaced from the beams to provide for passage of fluid.

4. A matrix as defined in claim 3 in which the marginal portions at the corresponding edges of the sheets are in abutment to terminate the passes, and holes are provided in the sheets adjacent the marginal portions thereof to connect adjacent passes.

References Cited by the Examiner UNITED STATES PATENTS 2,680,598 6/1954 Trulsson et a1. 9 2,977,096 3/1961 Evans 1657 FOREIGN PATENTS 147,208 7/ 1952 Australia.

ROBERT A. OLEARY, Primary Examiner.

A. W. DAVIS, Assistant Examiner. 

1. AN ANNULAR MATRIX FOR A ROTARY REGENERATOR COMPRISING, IN COMBINATION, TWO RIMS DEFINING THE MARGINS OF THE MATRIX, STIFFENERS DISTRIBUTED CIRCUMFERENTIALLY OF THE MATRIX EXTENDING BETWEEN AND CONNECTED TO THE RIMS, AND HEAT EXCHANGE MATERIAL HAVING TWO FACES AND PERVIOUS TO FLUID FLOW FROM FACE TO FACE THEREOF EXTENDING FROM ONE RIM TO THE OTHER BETWEEN THE STIFFENERS, EACH STIFFENER HAVING ONE EDGE ADJACENT EACH FACE OF THE HEAT EXCHANGE MATERIAL, CHARACTERIZED BY HOLLOW STIFFENER STRUCTURE DEFINING A FLOW PATH STARTING AT ONE EDGE OF THE STIFFENER AND TERMINATING AT THE OTHER EDGE OF THE STIFFENER, FOR CIRCULATING FLUID THROUGH THE STIFFENERS FROM EDGE TO EDGE IN RESPONSE TO THE PRESSURE GRADIENT OPERATIVE TO CAUSE FLUID FLOW THROUGH THE HEAT EXCHANGE MATERIAL FROM FACE TO FACE OF THE MATRIX, SAID STIFFENER STRUCTURE INCLUDING TWO BARS DISPOSED FACE TO FACE, AT LEAST ONE BAR BEING RECESSED TO DEFINE A PASSAGE WITHIN THE STIFFENER EXTENDING IN THE EDGE-TO-EDGE DIRECTION OF THE STIFFENER MEANS DEFINING HOLES IN BOTH EDGES OF THE STIFFENER COMMUNICATING WITH THE SAID PASSAGE AND BAFFLE MEANS WITHIN THE PASSAGE DEFINING A RETROVERSE PATH WITH AN ODD NUMBER OF MUTUALLY OVERLAPPING PASSES FOR THE FLUID IN THE DIRECTION FROM EDGE TO EDGE OF THE STIFFENER WITHIN THE PASSAGE. 